Electronics guru's need help identifying something again.

Kaervak

Diamond Member
Jul 18, 2001
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Originally posted by: Safeway
What is that on? Soldering job looks a little difficult.

G4 iBook motherboard. It has the famous random freezing issue. Figured it was the video chip like normal but found that while looking closer. Yeah solder work would be a massive pain, maybe conductive pen?
 

jmcoreymv

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Oct 9, 1999
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Those look like capacitors. Surface mount resistors usually have markings to indicate their value. Also the C# reference designator means capacitor.
 

Kaervak

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Jul 18, 2001
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Originally posted by: jmcoreymv
Those look like capacitors. Surface mount resistors usually have markings to indicate their value. Also the C# reference designator means capacitor.

Do you think it's repairable with solder if I'm extremely careful? Or would using a conductive pen be a better option?
 

jmcoreymv

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Oct 9, 1999
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Originally posted by: Kaervak
Originally posted by: jmcoreymv
Those look like capacitors. Surface mount resistors usually have markings to indicate their value. Also the C# reference designator means capacitor.

Do you think it's repairable with solder if I'm extremely careful? Or would using a conductive pen be a better option?

You can't really repair a cracked capacitor. It need's to be replaced, they are usually cheap, but you have to know the right kind to get (capacitance, tolerances, max voltage, etc). They are easy to replace with a soldering iron usually. I can't tell from your photo how big those are, but assuming they are 0603 that is definitely doable by hand. Any smaller than that gets tricky.
 

Kaervak

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Jul 18, 2001
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They're quite small. The thread diameter on the hex nut in the picture is 2mm. Those caps are probably 1mm at the most SOL probably.
 

jmcoreymv

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Oct 9, 1999
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Originally posted by: Kaervak
They're quite small. The thread diameter on the hex nut in the picture is 2mm. Those caps are probably 1mm at the most SOL probably.


If thats the case, they could be 0402 which is .04" by .02". Those are hard to do by hand, but they dont look crowded near other components, so it is still possible. You'd need a very fine tip soldering iron, and tweezer, and if possible a microscope.
 

jmcoreymv

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Oct 9, 1999
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Originally posted by: Kaervak
Well at least it's not completely hopeless. Thanks for the help. :)


Still pretty hopeless unless you find out the right capacitor to replace it with :)
 

Kaervak

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Jul 18, 2001
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Originally posted by: jmcoreymv
Originally posted by: Kaervak
Well at least it's not completely hopeless. Thanks for the help. :)


Still pretty hopeless unless you find out the right capacitor to replace it with :)

Good point.
 

GalvanizedYankee

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Oct 27, 2003
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Download sharp pics no bigger than 800x600 to the server at http://www.badcaps.net/ in
the appropriate forum.

willawake, arneson or Per will be of great help. It can be saved with a little effort and the right iron/tip.
Please give me the referral because we are competing :)


...Galvanized(badcaps nick)
 

Safeway

Lifer
Jun 22, 2004
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Originally posted by: GalvanizedYankee
Download sharp pics no bigger than 800x600 to the server at http://www.badcaps.net/ in
the appropriate forum.

willawake, arneson or Per will be of great help. It can be saved with a little effort and the right iron/tip.
Please give me the referral because we are competing :)


...Galvanized(badcaps nick)

Wow. ATOT has a capacitor replacement expert. Who-da-thunk-it.
 

GalvanizedYankee

Diamond Member
Oct 27, 2003
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Originally posted by: Safeway
Originally posted by: GalvanizedYankee
Download sharp pics no bigger than 800x600 to the server at http://www.badcaps.net/ in
the appropriate forum.

willawake, arneson or Per will be of great help. It can be saved with a little effort and the right iron/tip.
Please give me the referral because we are competing :)


...Galvanized(badcaps nick)

Wow. ATOT has a capacitor replacement expert. Who-da-thunk-it.

Not even close to being expert Safeway. I've recapped a couple cards, one mainboard and have a cheap PSU to do. I'm in the market for LCDs that need repair.

Knowing where to go for real help is over half the battle ;) A decent ESD safe soldering station is a big help.

They let me be a Mod there so I could ban spammers and delete thier posts.
Look the site over, they are a good bunch of techs. Some with 40+years experience.

 

Kaervak

Diamond Member
Jul 18, 2001
8,460
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Originally posted by: GalvanizedYankee
Download sharp pics no bigger than 800x600 to the server at http://www.badcaps.net/ in
the appropriate forum.

willawake, arneson or Per will be of great help. It can be saved with a little effort and the right iron/tip.
Please give me the referral because we are competing :)


...Galvanized(badcaps nick)

Ooooh yeah, I forgot about them. Thanks. :)
 

Colt45

Lifer
Apr 18, 2001
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replacing it is a piece of cake. finding out what the value is, is suck.
looks like an 0402

unless you can get a schematic or a partslist, you're more or less screwed. i guess you could try trial and erroring it.
 

Kaervak

Diamond Member
Jul 18, 2001
8,460
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81
Another question, how horrible for the laptop would it be to desolder that cap and then bridge the connection point with solder? I know it wouldn't be all that good in terms of possibly frying something, but would it work at all? And is it possible that those are redundant caps? One fails, the other takes over kinda thing.
 

henryay

Senior member
Aug 14, 2002
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It does look like the caps are in parallel to ground assuming that nut is also connected to the ground plane. So, that implies it is a decoupling cap most of the time.
 

Kaervak

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Jul 18, 2001
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Originally posted by: Kaervak
Another question, how horrible for the laptop would it be to desolder that cap and then bridge the connection point with solder? I know it wouldn't be all that good in terms of possibly frying something, but would it work at all? And is it possible that those are redundant caps? One fails, the other takes over kinda thing.

Anyone else have an opnion on my genius idea?
 

jmcoreymv

Diamond Member
Oct 9, 1999
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Originally posted by: Kaervak
Originally posted by: Kaervak
Another question, how horrible for the laptop would it be to desolder that cap and then bridge the connection point with solder? I know it wouldn't be all that good in terms of possibly frying something, but would it work at all? And is it possible that those are redundant caps? One fails, the other takes over kinda thing.

Anyone else have an opnion on my genius idea?

You definitely don't want to do that. If its a bypass capacitor, you just shorted power to ground.
 

Kaervak

Diamond Member
Jul 18, 2001
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Originally posted by: jmcoreymv
Originally posted by: Kaervak
Originally posted by: Kaervak
Another question, how horrible for the laptop would it be to desolder that cap and then bridge the connection point with solder? I know it wouldn't be all that good in terms of possibly frying something, but would it work at all? And is it possible that those are redundant caps? One fails, the other takes over kinda thing.

Anyone else have an opnion on my genius idea?

You definitely don't want to do that. If its a bypass capacitor, you just shorted power to ground.

LMAO, yeah that would be bad. Well it's not a total loss, as long as you're careful with moving the laptop it doesn't freeze up. Still would be nice to actually repair it, but better than nothing.
 

GalvanizedYankee

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Oct 27, 2003
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You should ask your questions over at badcaps.net ;)

Caps are in parallel inorder to lower ESR.
Caps normally fail in an open condition and no real harm is done.
Caps that fail in a shorted condition can/will kill hardware down stream.
Caps failing in PSUs can cause voltage spikes at BOOT, killing HDD logic chips.
Caps failing shorted have caused VRM/FETs to blow-up like itty-bitty firecrackers.
Rarely but it does happen before VRM/FETs pop, RAM or CPUs are killed.

So...Given the above, just jump the caps with solder and see what happens. We want a video :p


...Galvanized
 

Kaervak

Diamond Member
Jul 18, 2001
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Jeez I keep forgetting about badcaps. I would experiment, but it's not my laptop and if I fried it the owner would definitely be pissed.